There are 3 different versions:
- Original black Pro1 (QX1000), CPU: Snapdragon 835
- Planned blue Pro1-X (QX1050), CPU: Snapdragon 835 (only small batch produced)
- Latest blue Pro1-X (QX1050), CPU: Snapdragon 662 (also different camera)
You should select the firmware based on CPU. I think that nobody has highlighted the difference between SD835 QX1050 and SD662 QX1050 since so few SD835 QX1050 untis exist.